Variability of particulate matter concentrations along roads and motorways determined by a moving measurement unit

摘要: The spatial variability of aerosol number and mass along roads was determined in different regions (urban, rural coastal-marine) the Netherlands. A condensation particle counter (CPC) an optical spectrometer (LASX) were installedin a van with global positioning system (GPS). Concentrations measuredwith high-time resolutions while driving allowing investigations not possible stationary equipment. In particular, this approach proves to be useful identify those locations where numbers attain high levels (‘hot spots’). general, concentrations andmass particulate matter increase degree urbanisation, concentration being more sensitive indicator. lowest PM1-concentrations are encountered coastal andrural area: o5000 cm 3 and6 m gm , respectively. presence sea-salt material NorthSea coast enhances PM>1-concentrations comparedto inlandlevels. High-particle encounteredon motorways correlating traffic intensity; largest average is measuredon ring motorway aroundAmsterd am: about 160 000 (traffic intensity 100 veh day 1 ). Peak values occur tunnels exceed10 6 . EnhancedPM (i.e. larger than 9m ) exist on motorways, major tunnels. PM>1 appear rather uniformly distributed (below 6m for most observations). On urban scale, (large) variations can explainedby varying intensities andd riving patterns. highest measuredwhile congestions or when behind heavy diesel-driven vehicle (up 600 10 Relatively observedduring passages crossings and, at decreasing rate, main much traffic, quiet streets residential areas limited traffic. exhibits mass: city 12% higher area edge same particles changes by factor two (due ultrafine (aerodynamic diameter o100 nm). It further indicated that people residing some downwind source exposed (still) 40% living backgroundareas. r 2004 Elsevier Ltd. All rights reserved.